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ALC889 RMAA results at 24/44.1
markanini
post Dec 30 2011, 11:23
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Motherboard is a Gigabyte Z68XP-UD4.


Line out to line in:
http://nerdmoments.byethost7.com/24_44_1.htm
Output set at "50", input at "100", assumed to be nominal levels(?).

Headphone out at max output, unloaded, to line in. (Input reduced to "25"):
http://nerdmoments.byethost7.com/24_44_1_HP.htm

I can do some loaded test of the headphone pre-amp if anyone's interested. I have Ety HF5, Beyer DT250-80, Senn PX-100, Koss KTXPro1, Senn HD201 and Creative EP-630 at hand. I assume I need a 3,5 mm Y splitter with one male and one female connector at the split ends?

Note that while output is 24-bit capable input is 16-bit(oddly, both are 24-bit according to datasheet).

This post has been edited by markanini: Dec 30 2011, 12:04
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Arnold B. Kruege...
post Mar 25 2013, 20:02
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QUOTE (markanini @ Dec 30 2011, 06:23) *
Motherboard is a Gigabyte Z68XP-UD4.


Line out to line in:
http://nerdmoments.byethost7.com/24_44_1.htm
Output set at "50", input at "100", assumed to be nominal levels(?).


In other measurements I've found that a lot of chips used for on board audio interfaces have asymmetrical performance. IOW their ADCs aren't up to the quality levels of their DACs.

I recently did some testing of an ALC 887 chip on a Gigabyte system board and when looping it back through itself, found results similar to those posted above.

I then redid the tests looping the ALC 887 output through an M-Audio AP 24192 input - knowing that this interface has native performance with up to 110 dB dynamic range.

I obtained the following results:

Frequency response (from 40 Hz to 15 kHz), dB: +0.01, -0.08 Excellent
Noise level, dB (A): -92.4 Very good
Dynamic range, dB (A): 92.4 Very good
THD, %: 0.0028 Excellent
IMD + Noise, %: 0.030 Good
Stereo crosstalk, dB: -89.8 Excellent
IMD at 10 kHz, %: 0.0093 Very good

While I'm at it, I discovered a way to circumvent a problem that sometimes arises while testing different audio interfaces mixed and matched.

In this test I was never able to get a recording level of greater than -12 dB, which the Rightmark program had problems with. I simply had the Rightmark program save the wave file that it recorded, normalized it with Audacity, and then analyzed it. Since the noise level of the AP 24192 card is about 110 db below its normal FS input, the test was run under a condition where this was effectively 98 dB below the tests, and so errors due to the circumvention were still well below the dynnamic range that was observed.

This post has been edited by Arnold B. Krueger: Mar 25 2013, 20:13
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markanini
post Mar 25 2013, 22:19
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Try setting the main output to headphone mode. I remember gettting more volume and better rightmark results in loopbaack mode that way.

This post has been edited by db1989: Mar 27 2013, 14:54
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Arnold B. Kruege...
post Mar 27 2013, 14:52
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Tried setting output to headphones instead of speakers and obtained:

Frequency response (from 40 Hz to 15 kHz), dB: +0.01, -0.07 Excellent
Noise level, dB (A): -92.5 Very good
Dynamic range, dB (A): 92.6 Very good
THD, %: 0.0028 Excellent
IMD + Noise, %: 0.029 Good
Stereo crosstalk, dB: -90.1 Excellent
IMD at 10 kHz, %: 0.0092 Very good

This post has been edited by db1989: Mar 27 2013, 14:55
Reason for edit: deleting pointless full quote of post containing pointless full quote
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Posts in this topic
- markanini   ALC889 RMAA results at 24/44.1   Dec 30 2011, 11:23
- - xnor   QUOTE (markanini @ Dec 30 2011, 12:23) I ...   Dec 30 2011, 12:02
|- - markanini   QUOTE (xnor @ Dec 30 2011, 12:02) QUOTE (...   Dec 30 2011, 12:15
- - xnor   Alright. The audio chip is a Realtek ALC889 right?...   Dec 30 2011, 15:31
- - markanini   Yes.   Dec 30 2011, 17:10
- - markanini   Results for PX100: http://nerdmoments.byethost7.co...   Dec 31 2011, 07:44
|- - saratoga   Those look really bad. I'm assuming thats the...   Dec 31 2011, 07:53
- - markanini   Some sort of best case result with Etymotic HF5: h...   Dec 31 2011, 09:32
- - ErnestS   Make sure you change in realtek software "spe...   Dec 31 2011, 11:01
- - markanini   For the sake of comparison split loopback driving ...   Dec 31 2011, 12:33
- - markanini   Again for comparison, Sansa Fuze. Totally beats pr...   Jan 1 2012, 06:03
- - xnor   Indeed, the problems seem to be output impedance (...   Jan 1 2012, 12:01
- - markanini   Yeah, high output impedance. For fun here's t...   Jan 1 2012, 16:02
|- - ErnestS   I forgot about this topic. QUOTE (markanini ...   Mar 15 2013, 09:52
|- - stv014   QUOTE (ErnestS @ Mar 15 2013, 09:52) Acco...   Mar 25 2013, 18:22
- - markanini   I googled and couldnt find a straight answer to th...   Jan 1 2012, 16:47
|- - saratoga   QUOTE (markanini @ Jan 1 2012, 10:47) I g...   Jan 2 2012, 18:03
- - xnor   Hmm, from 1.5 kHz to 70 Hz there's a differenc...   Jan 1 2012, 19:34
- - skamp   The output impedance isn't just tied to the DA...   Mar 15 2013, 10:06
- - xnor   Z77 Extreme 4 motherboard - I measured about 80 oh...   Mar 25 2013, 19:45
- - Arnold B. Krueger   QUOTE (markanini @ Dec 30 2011, 06:23) Mo...   Mar 25 2013, 20:02
|- - markanini   Try setting the main output to headphone mode. I r...   Mar 25 2013, 22:19
|- - Arnold B. Krueger   Tried setting output to headphones instead of spea...   Mar 27 2013, 14:52
- - db1989   How not to post   Mar 27 2013, 14:58
- - stv014   ALC887 line output (rear jack) on an ASUS motherbo...   Mar 27 2013, 16:52


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